The invention relates to monitoring voice quality levels in substantially real time for communications over a packet-based data network.
Data networks are widely used to link various types of network elements, such as personal computers, servers, gateways, network telephones, and so forth. Data networks may include private networks (such as local area networks or wide area networks), and public networks (such as the Internet). Popular forms of communications between network elements across such data networks include electronic mail, file transfer, web browsing, and other exchanges of digital data.
With the increased capacity and reliability of data networks, voice communications and other forms of streaming communications over data networks have become possible. Voice communications over data networks are unlike voice communications in a conventional circuit-switched network, such as the Public Switched Telephone Network (PSTN), which provides users with dedicated, end-to-end circuit connections for the duration of each call. Communications over data networks, such as IP (Internet Protocol) networks, are performed using packets or datagrams that are sent in bursts from a source to one or more destination nodes. Voice data, and other forms of streaming data, sent over a data network typically share network bandwidth with conventional non-streaming data (e.g., data associated with electronic mail, file transfer, web access, and other traffic).
In a packet-based data network, each data packet is routed to a node having a destination address contained within the header of the packet. Data packets may be routed over separate network paths before arriving at the final destination for reassembly. Transmission speeds of the various packets may vary widely depending on the usage of data networks over which the data packets are transferred. During peak usage of data networks, delays added to the transfer of voice data packets may cause poor performance of voice communications. Voice data packets that are lost or delayed due to inadequate or unavailable capacity of data networks or resources of data networks may result in gaps, silence, and clipping of audio at the receiving end.
A need thus exists for a method and apparatus that monitors for real time voice quality levels in live calls in packet-based data networks.